Disabling programs from running at system startup

Using the System Configuration Utility to disable Startup items:

Windows98/ME/XP

1) Click START | RUN
2) Type MSCONFIG and hit ENTER
3) Click the STARTUP tab

4) Locate the item you wish to remove and UNCHECK the box next to the item name.
If you do not know the name of the item you wish to remove, scroll to the right to locate the file path of the desired item. In the above example, %VirusPath% is the item that needs to be removed.
5) After UNCHECKING the box, click APPLY and then OK.
6) Click YES when prompted to reboot your system.

Windows2000 and for an alternate method, see Editing The Registry

Disabling services from running at system startup

Using the System Configuration Utility to disable Services.

WindowsXP

1) Click START | RUN
2) Type MSCONFIG and hit ENTER
3) Click the Services tab

4) Locate the item you wish to remove and UNCHECK the box next to the item name.
5) After UNCHECKING the box, click APPLY and then OK.
6) Click YES when prompted to reboot your system.